2023 - Day 1

2023/01/PART1.md

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+--- Day 1: Trebuchet?! ---
+
+Something is wrong with global snow production, and you've been selected to take
+a look. The Elves have even given you a map; on it, they've used stars to mark
+the top fifty locations that are likely to be having problems.
+
+You've been doing this long enough to know that to restore snow operations, you
+need to check all fifty stars by December 25th.
+
+Collect stars by solving puzzles. Two puzzles will be made available on each day
+in the Advent calendar; the second puzzle is unlocked when you complete the
+first. Each puzzle grants one star. Good luck!
+
+You try to ask why they can't just use a weather machine ("not powerful enough")
+and where they're even sending you ("the sky") and why your map looks mostly
+blank ("you sure ask a lot of questions") and hang on did you just say the sky
+("of course, where do you think snow comes from") when you realize that the
+Elves are already loading you into a trebuchet ("please hold still, we need to
+strap you in").
+
+As they're making the final adjustments, they discover that their calibration
+document (your puzzle input) has been amended by a very young Elf who was
+apparently just excited to show off her art skills. Consequently, the Elves are
+having trouble reading the values on the document.
+
+The newly-improved calibration document consists of lines of text; each line
+originally contained a specific calibration value that the Elves now need to
+recover. On each line, the calibration value can be found by combining the first
+digit and the last digit (in that order) to form a single two-digit number.
+
+For example:
+
+```
+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet
+```
+
+In this example, the calibration values of these four lines are 12, 38, 15,
+and 77. Adding these together produces 142.
+
+Consider your entire calibration document. What is the sum of all of the
+calibration values?

2023/01/PART2.md

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+--- Part Two ---
+
+Your calculation isn't quite right. It looks like some of the digits are
+actually spelled out with letters: one, two, three, four, five, six, seven,
+eight, and nine also count as valid "digits".
+
+Equipped with this new information, you now need to find the real first and last
+digit on each line. For example:
+
+```
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen
+```
+
+In this example, the calibration values are 29, 83, 13, 24, 42, 14, and 76.
+Adding these together produces 281.
+
+What is the sum of all of the calibration values?

2023/01/sample.txt

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+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet

2023/01/sample2.txt

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+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen

2023/01/solution.ts

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+const sample = await Deno.readTextFile("sample.txt");
+const sample2 = await Deno.readTextFile("sample2.txt");
+const input = await Deno.readTextFile("input.txt");
+
+const wordsToNumbers: Record<string, number> = {
+  one: 1,
+  two: 2,
+  three: 3,
+  four: 4,
+  five: 5,
+  six: 6,
+  seven: 7,
+  eight: 8,
+  nine: 9,
+};
+
+const getNumberStringsFromString = (data: string): string[] =>
+  data.match(/(\d)/g) ?? [];
+
+const getNumberStringsAndNumberWordsFromString = (data: string): string[] =>
+  Array.from(
+    data.matchAll(
+      new RegExp(`(?=(\\d|${Object.keys(wordsToNumbers).join("|")}))`, "gi"),
+    ),
+    (x) => x[1],
+  );
+
+const replaceWordNumbersToNumbers = (data: string): string =>
+  data.replace(
+    new RegExp(Object.keys(wordsToNumbers).join("|"), "gi"),
+    (match) => String(wordsToNumbers[match]),
+  );
+
+const solvePart1 = (data: string): number =>
+  data
+    .split("\n")
+    .filter(Boolean)
+    .map(getNumberStringsFromString)
+    .map((numbers) => [
+      numbers[0],
+      numbers[numbers.length - 1],
+    ])
+    .map(([a, b]) => parseFloat(a + b))
+    .reduce((s, v) => s + v);
+
+console.log("Sample:", solvePart1(sample)); // 142
+console.log("Input", solvePart1(input)); // 55090
+
+const solvePart2 = (data: string): number =>
+  data
+    .split("\n")
+    .filter(Boolean)
+    .map(getNumberStringsAndNumberWordsFromString)
+    .map((numbers) => numbers.map(replaceWordNumbersToNumbers))
+    .map((numbers) => [
+      numbers[0],
+      numbers[numbers.length - 1],
+    ])
+    .map(([a, b]) => parseFloat(a + b))
+    .reduce((s, v) => s + v);
+
+console.log("Sample2:", solvePart2(sample2)); //281
+console.log("Input", solvePart2(input)); //54845